He applauded as Federer started to leave the stadium, then ran back onto the court, dropping onto his haunches and pumping his arms in triumph. All that, three days before the final.

Defending champion and No. 1 ranked Novak Djokovic will take on Andy Murray today for a spot against Nadal in Sunday’s final.

The latest Grand Slam meeting between Nadal and Federer - who’ve won 26 majors between them - was a semifinal worthy of a final.

Nadal didn’t excuse his celebration, but explained it as letting off steam.

“It’s a fantastic victory for me. Very, very happy playing against the greatest of the history in semifinals, big match on Rod Laver [court],’’ he said. “It’s one of the victories that’s going to stay in my mind forever. It’s a fantastic way to start the season.’’

Apart from the 11 consecutive points Federer lost after a 10-minute delay near the end of the second set, the match was tightly contested.

Nadal has labored with injuries since losing the US Open final, and he’d talked about having time off next month to let his sore shoulder heal. On the eve of the tournament, he hurt his knee while he sat in a chair at his hotel - and thought for a while that he wouldn’t be able to play at the Australian Open. He has played with his right knee heavily strapped, but has still won six straight matches.

The 10th Grand Slam meeting between Nadal and Federer equaled the record for individual major matchups since the Open era began in 1968. Ivan Lendl beat John McEnroe in seven of their 10 meetings. Nadal now leads Federer, 8-2.

Federer said it feels like Nadal plays his best tennis against him.

Last time the pair met in Australia, Nadal won the 2009 final in five sets. He had to console Federer as he sobbed during the trophy presentation.

“For me it didn’t feel any different, you know, a finals or a semis against Rafa,’’ Federer said of last night’s match. “It’s always an occasion . . . Yeah, it was the same.’’

It was easier to handle walking off the court immediately, though, and not having his emotions broadcast to millions of people.

“It’s nicer,’’ Federer said. “I prefer to walk off this way than having to go through the trophy ceremony after losing.’’

Nadal has won the last five Grand Slam matches they’ve played - four of them in finals. The last time they met in a Grand Slam semifinal was at the French Open in 2005, when Nadal beat the then-No. 1 ranked Federer en route to his first major title.

“We have had good matches over the years. I enjoy playing him. The crowd really gets into it, which is nice,’’ Federer said. “We have a lot of respect for each other.’’

For Nadal, the celebrations were more about his progress to the final rather than another win over Federer.

“That’s why, because . . . 24 hours to play my first match, I was in my room crying because I believe I didn’t’’ have the chance to play in Melbourne, he said. “Two weeks later I am here in the finals.’’

For his part, Federer thinks his rivalry with Nadal is still good for tennis.

“I hope it inspires future generations,’’ he said. “I always think he plays a bit better against me than against other players, but that’s good for him.’’

Even so, Federer didn’t hang around to watch Nadal’s celebration.

“I was slightly disappointed, obviously, leaving center court, because I felt like my game was good and I could have done something in the finals,’’ he said. “But I don’t have to worry about that now anymore. It’s fine. I feel OK now. You know, it’s in the past already.’’